/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.schema;

/**
 * <code>CopyField</code> contains all the information of a valid copy fields in
 * an index.
 * 
 * @since solr 1.4
 */
public class CopyField {

	private final SchemaField source;
	private final SchemaField destination;
	private final int maxChars;
	public static final int UNLIMITED = 0;

	public CopyField(final SchemaField source, final SchemaField destination) {
		this(source, destination, UNLIMITED);
	}

	/**
	 * @param source
	 *            The SchemaField of the source field.
	 * @param destination
	 *            The SchemaField of the destination field.
	 * @param maxChars
	 *            Maximum number of chars in source field to copy to destination
	 *            field. If equal to 0, there is no limit.
	 */
	public CopyField(final SchemaField source, final SchemaField destination,
			final int maxChars) {
		if (source == null || destination == null) {
			throw new IllegalArgumentException(
					"Source or Destination SchemaField can't be NULL.");
		}
		if (maxChars < 0) {
			throw new IllegalArgumentException(
					"Attribute maxChars can't have a negative value.");
		}
		this.source = source;
		this.destination = destination;
		this.maxChars = maxChars;
	}

	public String getLimitedValue(final String val) {
		return maxChars == UNLIMITED || val.length() < maxChars ? val : val
				.substring(0, maxChars);
	}

	/**
	 * @return source SchemaField
	 */
	public SchemaField getSource() {
		return source;
	}

	/**
	 * @return destination SchemaField
	 */
	public SchemaField getDestination() {
		return destination;
	}

	/**
	 * @return tha maximum number of chars in source field to copy to
	 *         destination field.
	 */
	public int getMaxChars() {
		return maxChars;
	}
}
